1. Field of the Invention
The invention relates to a flexible manufacturing system. The flexible manufacturing system includes: a machining device that machines a workpiece; a pallet changer that exchanges pallets between a standby position and a machining position in the machining device; a pallet storage room that stores pallets to which workpieces have been attached; and a conveyor that conveys the pallets between the pallet storage room and the pallet changer.
2. Description of the Related Art
For example, Japanese Patent Application Publication No. 2010-134900 (JP 2010-134900 A) describes an example of a conventional flexible manufacturing system (hereinafter, referred to as “FMS” in abbreviated form) that allows manufacturing of wide variety of products in small quantities. JP 2010-134900 A describes a technique of conveying pallets disposed in a pallet storage room to a standby position of a pallet changer in a prescribed order. Japanese Patent Application Publication No. 63-108411 (JP 63-108411 A) and Japanese Patent No. 2735561 describe that whether machining is possible is determined based on tool information on a machining device.
In the FMS described in JP 2010-134900 A, when a machining device is machining a workpiece at a machining position, a tool in use may be broken. In this case, the workpiece that is being machined is treated as a defective piece. Further, under abnormal tool conditions, a workpiece that has already been conveyed to the standby position of the pallet changer is also treated as a defective piece. However, the workpiece at the standby position has not been machined and thus is not a defective piece.